This project has as its primary objective the development and expansion of field-flow fractionation (FFF) methodology. Attempts will be made to increase, speed, accuracy, resolving power and size range, in order to handle more complex biomedical systems. In addition, collaborative efforts will be undertaken for specific applications of FFF to biological and biochemical problems, including viruses and viral assembly units, synaptosomes, micelles, acid mucopolysaccharides, polyribonucleotides, and other materials. Finally, basic theoretical studies will be undertaken to clarify the relationships between and capabilities of diverse separation methods.